[web] Add nonprofit discount FAQ to plans page (#34126)

Insert a new "Do you offer discounts for nonprofits?" accordion item
under the educational group discount question in the "Overleaf
multi-license plans" FAQ tab. Routes the "contact sales" link through
the existing `faqContactLink` mixin so click tracking stays consistent
with the other FAQ contact links.

Closes #33494

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
GitOrigin-RevId: 582517f1d1f1f7934610253c252cf0f8af2b68a2

services/web/app/views/subscriptions/plans/_plans_faq_tabs_2026.pug

@@ -82,6 +82,12 @@ mixin overleafGroupPlans
 			| .
 		+accordionItem('overleafGroupPlansQ3', 'Who is eligible for the educational group discount?')
 			| The educational discount for group subscriptions is for students or faculty who are using Overleaf primarily for teaching.
+		+accordionItem('overleafGroupPlansNonprofitDiscount', 'Do you offer discounts for nonprofits?')
+			span We offer discounts to qualified nonprofits for purchases of 20 licenses or more. Please
+			| !{' '}
+			+faqContactLink('/for/contact-sales')
+				span contact sales
+			| .
 		+accordionItem('overleafGroupPlansQ4', 'How do I add more licenses to my group subscription, and what will it cost?')
 			div
 				span You can add up to 20 licenses by going to